class F:
    def __init__(self, a):
        self.a = a

    def get_a(self):
        print('读取变量喽')
        return self.__a

    def set_a(self, value):
        print('设置变量喽')
        self.__a = value

    #   拦截对a的操作
    #   创建property对象，a存储的是对象地址
    a = property(get_a, set_a)


f01 = F(10)
f01.a = 200
print(f01.a)
print(f01.__dict__)
